The Million Mile Mission
A small band of believers urges NASA to take its next step—onto an asteroid.
- By Michael Klesius
- Air & Space magazine, July 2008
(Page 3 of 6)
“The first part of this study was to determine if we could make it to an asteroid with no modifications whatsoever to Orion and the launch vehicle,” says Korsmeyer. “But that would be pretty hard and hairy.”
The weight of the crew, plus all the water, food, oxygen, and other supplies needed for a long voyage, posed a huge constraint. So the study team reduced the crew from four people (the baseline for a lunar mission) to three or even two, which freed up room for supplies. The good news is that a six-month asteroid mission wouldn’t require advanced systems for recycling water and air; Orion’s should be good enough.
The group also wrestled with the problem of communicating with a spacecraft more than two million miles from home. “At even a near-Earth asteroid, you’re 10 voice-seconds away,” says Korsmeyer. “You’re not really conversing with Earth at that point. The whole nature of the interaction becomes like the old ship-to-shore communications, a fancy telegraph, a voicemail. Not in real-time.”
An asteroid-bound crew would therefore need to “bring mission control on board,” says Korsmeyer, in the form of highly automated decision-making software. “When something bad happens, which tends to happen quickly, the crew and systems will have to manage it on their own. This is something humanity hasn’t done yet. But that makes it the best of all possible testing grounds for Mars, which, without an asteroid mission, will be like jumping into the deep end without practicing in the shallow end.” In comparison, “the moon is like the baby pool. I don’t mean to minimize that—Apollo 13 showed us you can drown there too.” But, he says, an asteroid “would really be someplace fabulously new. You’re talking 2.5 million miles, more than 10 times the distance between Earth and the moon. You’d be so far away you could cover up Earth with your finger. It would be no more than a beautiful, pale blue star.”
The 2006 NASA study didn’t go into detail about what astronauts would do once they reached an asteroid. But results from Japan’s robotic Hayabusa mission, which in 2005 investigated the near-Earth asteroid 25143 Itokawa up close, have led to some intriguing speculations.
“Itokawa was one of the most heavily researched asteroids—radar, visible, infrared,” says Paul Abell, a scientist on contract with NASA from the Planetary Science Institute who participated in the Advanced Projects Office study. “Many countries and collaborators had studied it. But when we got there with Hayabusa we were surprised by what we saw.”
It turned out to be a rubble pile loosely held together by its own gravity. “It’s a sandbox,” Abell says, “about 40 percent porous. Lots of empty space, like you have in a jar full of marbles. That was a really profound discovery.”
The first asteroid to be explored by humans might look a lot like Itokawa. While scientists are reluctant to name a specific target when the mission hasn’t even been approved, two candidates tend to crop up on lists of NEOs that would be reachable in the next two decades. A tiny one called 1991 VG—just 40 by 14 feet, or about one-seventh the size of Itokawa—comes around in the year 2017, but is probably too small to be of interest. A more likely candidate, 1999 AO10, is the size of a football field. It could be reached in 2025, long after Orion starts flying. Both missions would require a round trip of 150 days.